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authorRaymond Hettinger <python@rcn.com>2010-11-30 07:13:04 (GMT)
committerRaymond Hettinger <python@rcn.com>2010-11-30 07:13:04 (GMT)
commit5e20bab42277d29aac36a011fe12d292ec5ab389 (patch)
tree8fc98d12e80971bc672035711ebbfcfd4ac02945
parent7921b9f2104fee46413798d0a82a1e822f061957 (diff)
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Neaten-up a bit.
-rw-r--r--Doc/library/functools.rst6
-rw-r--r--Doc/whatsnew/3.2.rst8
-rw-r--r--Lib/functools.py13
3 files changed, 12 insertions, 15 deletions
diff --git a/Doc/library/functools.rst b/Doc/library/functools.rst
index a8fc856..5b65874 100644
--- a/Doc/library/functools.rst
+++ b/Doc/library/functools.rst
@@ -72,10 +72,10 @@ The :mod:`functools` module defines the following functions:
A `LRU (least recently used) cache
<http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used>`_
- is indicated when the pattern of calls changes over time, such as
- when more recent calls are the best predictors of upcoming calls
+ works best when more recent calls are the best predictors of upcoming calls
(for example, the most popular articles on a news server tend to
- change every day).
+ change each day). The cache's size limit assurs that caching does not
+ grow without bound on long-running processes such as web servers.
.. versionadded:: 3.2
diff --git a/Doc/whatsnew/3.2.rst b/Doc/whatsnew/3.2.rst
index 91ab849..2d1f0ef 100644
--- a/Doc/whatsnew/3.2.rst
+++ b/Doc/whatsnew/3.2.rst
@@ -332,15 +332,13 @@ New, Improved, and Deprecated Modules
c.execute('SELECT phonenumber FROM phonelist WHERE name=?', (name,))
return c.fetchone()[0]
- XXX: update for Issue 10586 changes to cache statistics API
-
To help with choosing an effective cache size, the wrapped function is
- instrumented with two attributes *cache_hits* and *cache_misses*:
+ instrumented with info function:
>>> for name in user_requests:
... get_phone_number(name)
- >>> print(get_phone_number.cache_hits, get_phone_number.cache_misses)
- 4805 980
+ >>> get_phone_number.cache_info()
+ CacheInfo(maxsize=300, size=300, hits=4805, misses=980)
If the phonelist table gets updated, the outdated contents of the cache can be
cleared with:
diff --git a/Lib/functools.py b/Lib/functools.py
index c223a62..e8e9960 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -121,16 +121,15 @@ def lru_cache(maxsize=100):
Arguments to the cached function must be hashable.
- Significant statistics (maxsize, size, hits, misses) are
- available through the f.cache_info() named tuple.
- Clear the cache and statistics using f.cache_clear().
- The underlying function is stored in f.__wrapped__.
+ View the cache statistics named tuple (maxsize, size, hits, misses) with
+ f.cache_info(). Clear the cache and statistics with f.cache_clear().
+ And access the underlying function with f.__wrapped__.
See: http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used
"""
# Users should only access the lru_cache through its public API:
- # cache_info, cache_clear, and f.__wrapped__
+ # cache_info, cache_clear, and f.__wrapped__
# The internals of the lru_cache are encapsulated for thread safety and
# to allow the implementation to change (including a possible C version).
@@ -141,7 +140,7 @@ def lru_cache(maxsize=100):
cache_popitem = cache.popitem
cache_renew = cache.move_to_end
hits = misses = 0
- kwd_mark = object() # separate positional and keyword args
+ kwd_mark = object() # separates positional and keyword args
lock = Lock()
@wraps(user_function)
@@ -165,7 +164,7 @@ def lru_cache(maxsize=100):
return result
def cache_info():
- """Report significant cache statistics"""
+ """Report cache statistics"""
with lock:
return _CacheInfo(maxsize, len(cache), hits, misses)